A new look at geographic and phylogenetic relationships within the species group surrounding Octopus vulgaris (Mollusca, Cephalopoda): indications of very wide distribution from mitochondrial DNA sequences

Abstract

The distribution of Octopus vulgaris has not yet been completely clarified. For a long time, a cosmopolitan distribution with unknown distribution limits had been assumed. This assumption has recently been questioned and it has been postulated that the distribution is restricted to the Mediterranean and the northeastern Atlantic. However, as our previous studies show, the existence of O. vulgaris can be confirmed for the Mediterranean and the whole eastern Atlantic, and evidence is provided for its occurrence in the western Atlantic. The aim of the present work is to extend our previous data matrix and to clarify whether O. vulgaris exists in the northwestern Pacific. Therefore, the sequence variation in ostensible O. vulgaris from 13 localities in the Mediterranean (France), the Atlantic Ocean [Lanzarote, Senegal, South Africa (Atlantic, Indian Ocean), Tristan da Cunha, north, middle and south Brazil], the Caribbean Sea (Venezuela) and the Pacific Ocean (Taiwan, Japan and Costa Rica) was examined using the mitochondrial genes coding for the 16S rRNA and cytochrome oxidase subunit III (COIII). Sequence divergence was relatively low between populations of O. vulgaris from the Mediterranean, the eastern and western Atlantic (except north Brazil), Venezuela, Taiwan and Japan compared with other species of the genus Octopus. Trees constructed by using maximum likelihood, neighbour joining and maximum parsimony algorithms (PAUP) show the above-mentioned populations from the Mediterranean, the western and eastern Atlantic, Venezuela and the northwestern Pacific (Japan and Taiwan) as a monophyletic cluster.Thus, even if the Octopus vulgaris-like octopus from north Brazil should turn out a cryptic species, the data of this work not only support our hypothesis of the distribution of O. vulgaris in the Mediterranean, the eastern and western Atlantic but also show that O. vulgaris is present in the northwestern Pacific, namely in the waters of Taiwan and Japan.

Ethnoecological knowledge of the artisan fishermen of octopi (Octopus spp.) in the community of Coroa Vermelha (Santa Cruz Cabrália, Bahia)

“…Some authors estimate that the occurrence of this species is restricted to Mediterranean and the East portion of the Atlantic Ocean (Belcari et al 2002). However, DNA studies of distant populations have confirmed the occurrence of the same species also in western Atlantic Ocean and northwest of Pacific (Warnke et al 2004). …”

A contribution to the understanding of phylogenetic relationships among species of the genus <i>Octopus</i> (Octopodidae: Cephalopoda)

“…O. tehuelchus appears more closely related to the genera Callistoctopus, Grimpella and Macroctopus, as well as to "unplaced" Octopus species sensu Norman and Hochberg (2005), than to the clade containing most of the valid species of Octopus (Fig. 1) Söller et al (2000) and Warnke et al (2004) and identified as a new species, O. insularis, by Leite et al (2008) In the last few years, studies on the molecular systematics of octopuses have helped to clarify their confusing systematics and phylogenetic relationships and also to identify and describe new species (Norman and Hochberg 2005, Allcock et al 2007, Leite et al 2008, Strugnell et al 2009). In the present study, we focused on the genus Octopus using a Bayesian approach to estimate the phylogenetic relationships among published sequences of the COIII gene of Octopus species, of O. tehuelchus from the southwestern Atlantic Ocean (a species never included in phylogenetic analyses of the genus before), and of individuals of O. mimus from newly sampled localities in the Pacific Ocean (Chile and Peru).…”

“…vulgaris specimens are included in two different, well-supported clades, with O. insularis as their sister group. These specimens were considered by Söller et al (2000) and Warnke et al (2004) as part of the O. vulgaris species complex, but Leite et al (2008) described them morphologically, established their molecular distinctiveness and phylogenetic position using the 16S rRNA gene, and assigned them the name O. insularis. In the papers by Söller et al (2000) these specimens group with other O. vulgaris forming a monophyletic clade, but they do not include other species of Octopus.…”

“…To resolve the incompletely described and wide geographic range of O. vulgaris, Warnke et al (2004) estimated phylogenetic relationships among O. vulgaris from several localities, including South Africa, Tristan da Cunha (South Atlantic), West Africa, Japan, southern Brazil and the Caribbean, and compared the sequences of the COIII and 16S genes with those of O. mimus specimens from Chile and the Pacific coast of Costa Rica. They confirmed a previous result by Söller et al (2000) that O. mimus and O. vulgaris are separate lineages, and concluded that the monophyly of O. vulgaris was supported.…”

“…Warnke et al (2004) used COIII and 16rRNA genes to clarify the limits and distribution of the species O. vulgaris. They revealed that populations from the Mediterranean, the western and eastern Atlantic, Venezuela, Japan and Taiwan form a monophyletic clade, confirming the presence of the species in the north-western Pacific.…”